The present invention relates to a device for sealing between an element for partitioning two separate regions and a given fixture placed in front of an aperture formed in the said partition.
In certain fields, such as that of motor vehicles, it is often sought to achieve sealing of fixtures fixed onto support partitions by way of a sealing gasket arranged on the periphery of the aperture of the partition and against which the corresponding periphery of the fixture will be applied, the fixture being intended to pass through the said aperture in such a way as to allow communication between the said regions which are arranged on either side of the partition.
It is in this way that the air-distribution units for heating, ventilation and air-conditioning (HVAC) are fixed onto a partition, constituting an interface or bulkhead, generally produced from sheet metal, and arranged between the passenger cabin of a motor vehicle and an engine compartment.
In this way, sealing is provided for the air inlet or outlet between the passenger cabin of the vehicle and the outside.
In a way which is also known, this type of gasket is obtained by cutting-out from polyurethane foam which is then bonded onto the components.
Furthermore, it is also known to soundproof at least one of the sides of the metal interface or bulkhead by application of a soundproofing coating.
In the region of the aperture which is intended for installation of the air-distribution unit for heating, ventilation and air-conditioning, it is known to form a cut-out, in the soundproofing coating, the cut-out having dimensions greater than those of the aperture so as to clear the periphery thereof and to allow application of a sealing gasket interposed between a peripheral region of the aperture, left free, and a corresponding region of the fixture to be fixed, in this instance to a heating- and ventilation-air distributor.
The prior art which has just been cited is illustrated in FIG. 1, where a fixture a is seen which is applied against a bulkhead b by way of a gasket made of polyurethane foam c arranged around an aperture d of the bulkhead b, the latter moreover having received a soundproofing coating e in which an aperture f has been formed so as to allow the application of the gasket c against the bulkhead b. The soundproofing coating e is also made of polyurethane, but coated on its visible face with a skin of dense rubber g.
It will easily be understood that such a way of working exhibits a fair number of drawbacks, one of them being caused by the fact that, with the soundproofing coating being cut out over dimensions which are much larger than those of the aperture d of the partition b, a non-soundproofed region results between the gasket c and the soundproofing coating e, this non-soundproofed region consisting, to be exact, of the aperture f formed in the coating e.
Moreover, this solution implies not only the manufacture of a separate gasket but also a supplementary handling operation consisting in coating it with adhesive and putting it in place on the duct a.
Another drawback lies in the fact that an affixed gasket is always subject to leaks.
Another important drawback resulting from the prior art in this field consists in the fact that the technical definition and the responsibility for production of the soundproofing coating lay with whoever assembled the bulkhead onto the vehicle, whereas those for the sealing gasket lay with whoever assembled the air-distribution unit for heating, ventilation and/or air-conditioning. This separation of the functions requires coordination of the activities of each of the participants, which is not an easy matter.
According to a first phase of the inventive step, it has been observed that, in fact, the soundproofing coating mentioned above was generally made up of a thickness of polyurethane foam, that is to say of a substance identical to that of the sealing gasket affixed between the unit and the periphery of the aperture deliberately left clear, the only difference between the two materials constituting, on the one hand, the gasket and, on the other hand, the soundproofing coating, lying in the fact that the latter, on its free face opposite its face for contact with the bulkhead, includes a skin of dense rubber with a thickness of about two millimetres constituting a heavy mass, intended to form a high-frequency vibration filter.
These latter observations, associated with those mentioned above, led to a solution to the problems posed and which have just been cited.
To that end, the invention relates to a device for sealing between an element for partitioning two distinct regions and a given fixture, placed in front of an aperture formed in the partition, against one of its faces receiving a soundproofing coating, in such a way as to allow communication between the said regions through the fixture, by way of a sealing gasket, characterised in that the said sealing gasket consists of an extension of the soundproofing coating itself, in the direction of the peripheral edges delimiting the aperture of the partition and with a value such as to allow integral peripheral contact with a peripheral region of the fixture to be put in place.
The present invention also relates to the characteristics which will emerge in the course of the description which will follow, and which should be considered in isolation or in all their possible technical combinations.